1. Field of the Invention
The present invention relates to a travel route searching method of a mobile object in a navigation system from a current position to a destination. More particularly, the present invention relates to a travel route searching method of a mobile object using a road preferred by a user of the mobile object, a travel pattern at a crossroad and a road recommended by other users.
2. Description of the Related Art
As the number of various vehicles such as passenger cars continuously increases, traffic congestion becomes more critical. Particularly, there is a serious problem in that the increase rate in the number of vehicles is much faster than that of infrastructure such as road, bridge or the like. As one of the solutions to such traffic congestion, attention has been paid to a navigation system for guiding a travel path of a vehicle using a navigation system known as Global Positioning System (GPS).
In a navigation system using the GPS, a GPS receiver receives navigation messages transmitted by a plurality of GPS satellites in order to detect a location at which the navigation messages are received, i.e., a current vehicle location, using the received navigation messages, and the detected current vehicle location is map-matched on a digital map data so that the digital map data and the current vehicle location can be displayed on a display screen.
Therefore, the vehicle user can beforehand search or plan a travel route from the current vehicle location to a destination and under the guidance of the navigation system, the vehicle user can move a vehicle along the searched travel route. Accordingly, when the navigation system is used, the travel route of the vehicle can be searched and guided, resulting in an efficient use of the given road systems.
In the conventional navigation system by which a search is made for a travel route from a current location of a vehicle to a destination, a shortest route is searched using the map date stored in a map data storage, or a travel route is searched using a preference search of a highway or a freeway.
The navigation system is used for receiving traffic information via a public communication network, and the received traffic information is further used to search a travel route of a mobile object, enabling to avoid a congested road.
However, the conventional method thus mentioned has been to search a travel route of a vehicle without reflecting information of a road preferred by a vehicle user, a travel pattern and the like. Therefore, there is a limit in searching for an optimum travel route specifically wanted by a vehicle user.
In other words, there are cases where, in moving a mobile object from a current location to a destination, a vehicle user wants to travel to a destination along a scenic road instead of using a broad road. Furthermore, there is a travel pattern preferred by a vehicle user such as a U-turn, a straight run, a right turn or a left turn at every crossroad.
The travel route of a vehicle user has been searched in the past without consideration to a travel preference of the vehicle user for each road from a current location of a vehicle to a destination and a travel pattern at each crossroad. Accordingly, there is a limit in searching an optimum travel route for a vehicle user, resulting sometimes in a case where a searched travel route in a navigation system is avoided by the vehicle user who then travels along another travel route.
There is a case where a vehicle is used by plural users, and in this case, other users may recommend a scenic route or a route where it is convenient to steer a vehicle and traffic is less congested. However, there is a problem in the conventional navigation system thus explained in that a travel route has been searched without any consideration to the other users' recommendation.